Inhibition of precipitation and aggregation of metacinnabar (mercuric sulfide) by dissolved organic matter isolated from the Florida Everglades

Journal Article · Sat May 01 04:00:00 EDT 1999 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es9811187· OSTI ID:354344

Ravichandran, M; Ryan, J N ^[1]; Aiken, G R; Reddy, M M ^[2]

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1. Univ. of Colorado, Boulder, CO (United States). Dept. of Civil, Environmental, and Architectural Engineering
2. Geological Survey, Boulder, CO (United States)

Precipitation and aggregation of metacinnabar (black HgS) was inhibited in the presence of low concentrations of humic fractions of dissolved organic matter (DOM) isolated from the Florida Everglades. At low Hg concentrations, DOM prevented the precipitation of metacinnabar. At moderate Hg concentrations, DOM inhibited the aggregation of colloidal metacinnabar At Hg concentrations greater than 5 {times} 10{sup {minus}4} M, mercury formed solid metacinnabar particles that were removed from solution by a 0.1 {micro}m filter. Organic matter rich in aromatic moieties was preferentially removed with the solid. Hydrophobic organic acids inhibited aggregation better than hydrophilic organic acids. The presence of chloride, acetate, salicylate, EDTA, and cysteine did not inhibit the precipitation or aggregation of metacinnabar. Calcium enhanced metacinnabar aggregation even in the presence of DOM,m but the magnitude of the effect was dependent on the concentrations of DOM, Hg, and Ca. Inhibition of metacinnabar precipitation appears to be a result of strong DOM-Hg binding. Prevention of aggregation of colloidal particles appears to be caused by adsorption of DOM and electrostatic repulsion.

• OSTI ID: 354344
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 9 Vol. 33; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AGGLOMERATION
EVERGLADES NATIONAL PARK
FLORIDA
HUMUS
INHIBITION
MERCURY SULFIDES
PRECIPITATION
WATER CHEMISTRY
WATER POLLUTION